According to the development of wireless communication technology, interest in wireless power transceiving technology which provides electric power to electronic devices wirelessly is increasing. The wireless power transceiving technology may be diversely applied to a power supply for household electronic products and for electric cars or subway trains, as well as battery charging of portable terminals.
General wireless power transceiving technology uses a principle of magnetic induction or magnetic resonance. For example, when electrical energy is applied to a transmission antenna of a wireless power transmission device, the transmission antenna may convert the electrical energy into electromagnetic energy and emit the electromagnetic energy to the surroundings. And a receiving antenna of a wireless power receiving device may receive the electromagnetic energy emitted from the transmission antenna and convert it to the electrical energy.
In that case, it is necessary to minimize an energy loss between the wireless power transmission device and the wireless power receiving device to increase power transceiving efficiency. For this, the transmission antenna and the receiving antenna may need to be mutually arranged within an effective distance. Further, a soft magnetic material may be disposed around the transmission antenna and the receiving antenna to focus the electromagnetic energy emitted from the transmission antenna toward the receiving antenna.
For this, a receiving coil is formed on a soft magnetic layer. In that case, an air layer is formed between the receiving coil and the soft magnetic layer, and therefore there may be a problem that guiding effect of a magnetic field of the soft magnetic layer is reduced.